Fluid motor vent check valve assembly



April 21, 1953 A. ROBB I FLUID MOTOR VENT CHECK VALVE ASSEMBLY 2SHEETS-SHEET 1 Filed Feb. 20, 1950 INVENTOR Alexander L. Robb.

BY Camwwn, Mm rjul'l'w ATTORNEYS April 21, 1953. A. L. ROBB' 5 5 9 IFLUID MOTOR VENT CHECK VALVE ASSEMBLY Filed Feb. 20. 1950 2 SHEETS-SHE T2' 6 I mvENT'oR" Alexander L Robb.

I BY

I ATTORNEYS Patented Apr. 21, 1953 FLUID MOTOR VENT cHEcK VALVE ASSEMBLYAlexander -L-. Robb, Redwood City, Calif-.-, assignor to Hodges Researchand Development Company, Redwood City, Calif., a corporation ofCalifornia Application February'zo, 1950, Serial No. 145,106

Claims.

This invention relates to fluid motor vent check valve assemblies andmore particularly to such assemblies for use with fluid motors whichmove during use and which are reversible -by reversing the direction offluid flow thereto. More particularly this invention relates to fluidmotor vent check valve assemblies in which the vent conduit from themotor housing is in communication with the fluid pressure supply lineand with the fluid return line of the fluid motor through check valveswhich automatically connect the vent conduit to the low pressure orfluid return line.

In the co-pendin-g application of William C. Hodges and Alexander L.Robb, Serial No. 124,592, filed October 31, 1949, a fluid motor poweredmechanism is there disclosed. and claimed having a sprocket to move thepowered mechanism along a track to supply motive power for transferringless than carload lot containers to and from various means oftransportation. The fluid motor of this powered mechanism is suppliedwith fluid under pressure from a suitable source through a supply lineand a return lineis provided "from the motor housing to return the fluidfrom the motor to the source of fluid under pressure. The supply andreturn lines are suitable flexible conduits of considerable length toallow for the travel of the powered mechanismon the tracks. Theflui'dmotor there disclosed can be any of the various fluid motors knownto the art and reversal of the motor and reversal of the direction ofmovement of the powered mechanism is obtained by reversin'g'the conduitor line applying fluid under pressure to the motor. In other words, whenthe direction of movement of the motor is reversed the line formerlysupplying fluid under pressure becomesthe return line and the lineformerly the return line becomes the line for fluid under pressure.

All commercially availablefluid motors of the type suitable for'use withthis mechanism require a vent from the motor housing to vent fluidtherefrom leaking around the various parts of the motor and such a ventis customarily con-- nected to 'thelow pressure or retur n line of themotor to return the vented fluid to the source offluid supply. However,when it is desirable to reverse the directionof rotation of the motor atwill it is necessary to suitably connect the vent line so that it willbe automatically placed in communication with whichever of the two:motor lines :is the low pressure line. The fluidmotor vent check valveassembly of the present invention autoniaticall y a ccom zvlishes theconnection 2 of the motor vent line to whichever of the motor lines isthe low pressure line.

It is accordingly an object of the present inventionto provide a fluidmotor vent check valve assembly in which the fluid motor vent line isautomatically connected to whichever oi the fluid motor lines is the lowpressure or return line.

Another object of the present invention is to provide such a. vent checkvalve assembly which may readily and easily be installed on conventionalfluid motors.

Another object is to provide such a vent check valve assembly which iscompact; 'of'simple-des'ign and construction; and which includesconnections for the fluid motor lines. 7

Other and further objects of the present invention will appear from thefollowing description. The vent -nove1 check valveassembly of thepresent invention is capable-of various mechanical embodiments one ofwhich is shown in the accompanying drawing and is described hereinafterfor purposes -'of illustrating the same. This illustrative embodiment ofthe present invention should in no way be construed as defining orlimiting the same and reference should be had to the appended claims forthis purpose.

In the "accompanying drawings, in which like reference charactersindicate like par-ts,

Fig. 1 is a side view of a fluid motor having one embodiment of thenovel fluid motor vent check valve assembly of the present inventionincorporated therewith;

Fig. 2 is -an end view of the check valve assembl-y'of Fig. 1 partiallyin section-to showthe positioning of the several parts thereof;

Fig. 3 is across-sectional View on the line 3--3 'o'fFi 2; and

Fig. 4 isan expanded view of the several elements of one'of the checkvalves.

Referring now to the several figures, and in particular "to Figs. -1 and2, iii is the housing of any conventional fl-uid motor driven by fluidunder pressure. A suitable rotor, not shown, is mounted in housing 10and drives a. shaft, which is not-shown, which inturn supports a gear,not shown, in housing I I and this gear may' be a part of the geartraindescribed in the above identified application which 'gear train ismounted within the framework'gene'rally indicated at 42. Housing 10 isprovided with apa'ir of outwardly extending'boss'es Hand-1'4 toreceivethe fluid lines to supply fluid to and ito 'retur-n fluid from themotor. Bosses I a-and l4=are-prov ided with-conduits --extending intothe motor and these conduits-may be internally threadedat I 5. Housingfil is provided with a 'flu id 'vetit aperture i=6 into gasket 55 byspring 51.

which may be screwed an elbow l1 and a suitable vent line I8 is incommunication with elbow H.

The novel fluid motor vent check valve assembly of the present inventionis mounted on bosses I3 and I4 and comprises a housing [9 which isprovided with suitable couplings 26 and 2| to receive the fluid motorlines. Connections and 2| may if desirable be any suitable type of quickconnect coupling. Housing [9 is provided with a pair of cylindricalchambers 22 and 23 to receive studs 24 and 25 respectively and studs 24and 25 are threaded at their inner ends at 26 for engagement withthreads 15 within bosses l3 and I4. Studs 24 and 25 pass through block|9 and are threaded at their outer extremities at 21. A washer '28 andnut 29 are mounted on the outer extremity of studs 24 and 25 to lockhousing |9 against bosses I3 and I4. Gaskets 30 and 3| and an O ring onstud 24 may be provided to obtain a fluid tight seal between washer 28and housing i9; between housing |9 and bosses l3 and I4 respectively(Fig. 3) and between stud 24 and washer 28. Studs 24 and 25 are axiallybored at 32 .and bore 32 opens into a cross conduit 33. Conduit 33 ofstud 24 is in communication with passage 34 leading from coupling 25 andconduit 33 of stud 25 is in communication with passage 35 leading fromcoupling 2|.

Housing I9 is also provided with a pair of chambers 36 and 31 to receivethe check valves .to be described in more detail hereinafter. Chamber 36communicates through opening 38 with chamber 22 and conduit 33 of stud24 and chamber 31 communicates through opening 39 with chamber '23 andconduit 33 of stud 25. Chambers 36 and 31 are preferably of cylindricalform and are closed at their upper ends by plates 46 and 4| respectivelywhich are secured to housing l9 by suitable screws or studs 42. A

I8. Fluid vented from motor housing |0 will therefore pass :through line|8 into conduit 43 and into the vcheck valve chambers 36 and 31.

A. suitable check valve is mounted in chambers 36 and 31, which is shownmore particularly in Figs. 3 and 4, and is seen to comprise a valve seatmember 46 which is secured to the adjacent cover plate 49 or 4| by asuitable stud 41'. .Seat member 46 is circumferentially grooved at '41and 48 to receive suitable gaskets 49 and 50 :respectively to form fluidtight seals with chambers 36 and 31. Seat member 46 is alsocircumferentially cut away at 5| and is cross bored .at 52 and 53..bored at 54 and bore 54 communicates with the ;intersection of crossbores 52 and 53 and opens through the lower end of seat 46. Seat member46 may also mount a suitable gasket 55 in its Seat member 46 is alsoaxially lower end to form a fluid tight seal with the valve element 56.

Valve element 56 is shown in detail in Fig. 4

and is seen to comprise an octagon shaped ele- .ment fitting loosely inchambers 36 or 31 to per- .mit the passage of fluid around the edgesthereof. Valve element 56 is held in engagement with the underside ofseat member 46 and against Spring 51 is mounted in a suitable springseat and valve stop member 58 which is carried in the bottom of chambers36 and 31. Springseat and valve stop member 4 58 is provided withupstanding portions 59 to stop downward movement of valve element 56 andwhen valve element 56 is resting on elements 59 fluid can flow throughports 66 into openings 38 or 39.

With my novel fluid motor vent check valve assembly assembled as abovedescribed with a fluid motor whose direction of rotation is reversibleassume that fluid under pressure is first supplied to the motor throughthe conduit or line connecting with coupling 2|, The line connectingwith coupling 29 is therefore the low pressure or return line. Fluidunder pressure from coupling 2| passes through conduit 35 into chamber23 and thence through conduits 33 and 32 in stud 25 into the motorhousing I6. Fluid under pressure also passes from conduit 33 of stud 25into aperture 39 into the lower end of chamber 31 and passing upwardlythrough spring seat and valve stop member 58 impinges against the undersurface of valve element 56 and forces the same against gasket 55 toclose fluid communication through seat member 46. Fluid returning frommotor housing I9 passes through conduit 32 of stud 24 and into conduit33 thereof and thence outwardly through conduit 34 to coupling 26 forreturn to the source of fluid. The fluid passing through conduits 32,33, 34 and through coupling 26 creates a negative pressure throughorifice 33 within chamber 36 so that the only force holding valveelement 56 against seat in chamber 36 is that of spring 51. Duringoperation of the motor fluid will leak past the moving elements thereofinto the housing Ill and will pass outwardly therefrom through orificel6 and into conduit 13 and will pass from conduit l8 to vented fluidconduit 43 in valve block L3. The fluid in conduit 43 will be underpressure which is not suflicient to overcome the sum of the pressures ofthe fluid and of the spring pressure acting against valve element 56 inchamber 31 but is suflicient to overcome the spring pressure which isthe sole pressure acting against valve element 56 in chamber 36.Consequentl valve element 56 will be moved away from seat 46 and thefluid in conduit 43 will pass around valve element 56 and throughorifice 39 into chamber 22 and into conduit 33 and thence throughconduit 34 into coupling 29 for return to the source of fluid.

If the direction of rotation of the motor is now reversed fluid underpressure is supplied to coupling 26 and coupling 2| becomes the lowpressure or return line coupling. Under these circumstances the valveelement 56 in chamber 36 is held against its valve seat by the combinedforces of its spring and of the pressure of the incoming fluid and thevalve element 56 in chamber 31 is held against its seat by the force ofits spring 51 alone. Vented fluid under pressure in conduit 43 will thenopen the valve element 56 in chamber 3'! and the vented fluid will passthrough orifice 39 into chamber 23 and through conduit 35 into coupling2| for return to the source of fluid. It is therefore obvious that nomatter which of couplings 26 or 2| may be the pressure coupling andwhich may be the return coupling the check valves provided in chambers36 and 31 will automatically admit fluid vented from housing In to thelow pressure or return coupling for return to the source of fluid.

It will now be apparent that by the present invention I have provided anovel fluid motor vent check valve assembly which in every way satisfiesthe severalobjectives definedabove and which automatically admits ventedfluid to the low pressure or return line of the motor.

Changes to or modifications of the above described illustrativeembodiment of my invention may now be suggested to those skilled in theart without departing from my inventive concept and reference should behad to the appended claims to determine the scope of this invention.

What is claimed is:

1. In a valve assembly as described including a fluid motor housinghaving a pair of motor fluid conduits therein, a fluid vent aperture,and hollow studs extending from the pair of motor fluid conduits, avalve housing, a pair of chambers in said housing to receive the studs,a motor fluid line coupling mounted on said housing and communicatingwith one of said chambers, a second motor fluid line couplingcommunicating with the other of said chambers, the hollow studsconnecting said chambers and the adjacent one of the pair of conduits, acheck valve chamber in communication with each of said pair of chambers,a check valve in each of said check valve chambers normally blockingcommunication through said chambers, a vented fluid conduit in saidhousing communicating with said check valve chambers and incommunication with the vent aperture, and means resiliently urging saidcheck valves toward closed position against the pressure of the ventedfluid in said vented fluid conduit.

2. In a valve assembly as described including a fluid motor housinghaving a pair of motor fluid conduits, a fluid vent aperture, a valvehousing, and means for securing the valve housing to the motor housingover the motor fluid conduits, a pair of chambers in the valve housingin communication with the adjacent motor fluid conduit, a motor fluidline coupling communicating with each of said chambers, a check valvechamber in the valve housing communicating with each of said pair ofchambers, a check valve in each of said check valve chambers normallyblocking communication through said chambers, a vented fluid conduit inthe valve housing communicating with said check valve chambers and incommunication with the fluid vent aperture, and means resiliently urgingsaid check valves toward closed position against the pressure of thevented fluid in said vented fluid conduit.

3. In a valve assembly as described including a fluid motor housinghaving a pair of motor fluid conduits, a fluid vent aperture, and avalve housing, a fluid passage through the valve housing communicatingwith one of the motor fluid conduits, a second fluid passage throughsaid housing communicating with the other of the motor fluid conduits, acheck valve chamber for each of said fluid passages and in communicationtherewith, a check valve in each of said check valve chambers normallyblocking communication through said chambers, a vented fluid conduit inthe valve housing communicating with said check valve chambers and incommunication with the fluid vent aperture and means resilientlyurgagainst the pressure of the vented fluid in said vented fluidconduit.

4. A valve assembly as described in claim 3 in which each of said checkvalves includes a valve seat member closing one end of the associatedcheck valve chamber, a conduit in said seat member communicating withsaid vented fluid conduit, a valve element in said valve chamber, and aspring urging said valve element into engagement with said valve seatmember to close said conduit.

5. A valve assembly as described in claim 3 in which each of said checkvalve chambers opens through a side of said housing, and in which eachof said check valves includes a valve seat member closing the open endof the associated, check valve chamber, a plate secured to said seatmember and to the side of said housing, a conduit in said seat membercommunicating with said vented fluid conduit, a valve element in saidvalve chamber, and resilient means urging said valve element intoengagement with said valve seat member to close said conduit.

ALEXANDER L. ROBB.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,503,646 Fish Aug. 5, 1924 2,090,512 Ernst Aug. 17, 19372,399,907 Blair May 7, 1946 2,400,658 Sheppard May 21. 1946

